Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
A number of scientific methods have been developed to detect and/or measure one or more analytes in a biological or other environment. The one or more analytes could be any analytes that, when present in or absent from a person's body, or present at a particular concentration or range of concentrations, may be indicative of a medical condition or health state of the person. The one or more analytes could be substances whose distribution, action, or other properties, interactions, or activities throughout an animal's body was of scientific interest. The one or more analytes could be cofactors, substrates, products, or other substances related to a drug under development. The one or more analytes could be present in living or nonliving human or animal tissue, and could be detected and/or measured in an in vivo, ex vivo, in vitro, or some other type of sample. The one or more analytes could include enzymes, reagents, hormones, proteins, cells or other molecules.
Detecting and/or measuring one or more analytes in a biological or other environment can be accomplished through the use of an imaging or contrast agent targeted to the one or more analytes. The contrast agent can facilitate detection and/or measurement of the one or more analytes by having an optical, magnetic, electromagnetic, acoustical, and/or some other property that is detectably different from the surrounding environment. Detection of the targeted contrast agent in the environment could be used as a proxy for detection of the one or more analytes. For example, the contrast agent could absorb light of a first wavelength and emit light of a second wavelength in response to absorbing the light of the first wavelength. The contrast agent could be detected by emitting light of the first wavelength into the environment (e.g., a lumen of vasculature of a person's body) and detecting light of the second wavelength that is emitted from the environment in response to emitting the light of the first wavelength.